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1.
To find the optimal routing is always an important topic in wireless sensor networks （WSNs）. Considering a WSN where the nodes have limited energy, we propose a novel Energy^＊Delay model based on ant algorithms （＂E＆D ANTS＂ for short） to minimize the time delay in transferring a fixed number of data packets in an energy-constrained manner in one round. Our goal is not only to maximize the lifetime of the network but also to provide real-time data transmission services. However, because of the tradeoff of energy and delay in wireless network systems, the reinforcement learning （RL） algorithm is introduced to train the model. In this survey, the paradigm of E＆D ANTS is explicated and compared to other ant-based routing algorithms like AntNet and AntChain about the issues of routing information, routing overhead and adaptation. Simulation results show that our method performs about seven times better than AntNet and also outperforms AntChain by more than 150% in terms of energy cost and delay per round. 相似文献
2.
无线ad hoc网络最小均方负载均衡路由算法 总被引：1，自引：0，他引：1
Routing algorithm is a challenge for a mobile ad hoc network (MANET), but current routing protocols for MANETsconsider the path with minimum number of hops as the optimal path to a given destination. This strategy does not balancethe traffic load over a MANET, and may result in some disadvantages such as creating congested area, depleting power fasterand enlarging time delay in the nodes with heavy duties. In this paper, we propose a routing scheme that balances the loadover the network by selecting a path based on its mean load-square, the proposed routing metric can reflect not only the loadof the path, but also the load distribution along the path. Simulation results show effectiveness of this routing scheme onbalancing the load over all nodes in the network. 相似文献
3.
The expectations for sensor networks are growing. The performance of wireless sensor networks （WSNs） is greatly influenced by their network topology. In this paper, we consider four patterned topologies that best support connectivity among these deployed sensor nodes in two-tiered WSNs. The theoretical and simulation results show that the triangle-based topology has smaller cell number, shorter maximum hop length, less total energy consumption, and better performance than other topologies. The analysis carried out in this paper could provide the guidelines for network deployment and protocol design in the future applications. 相似文献
4.
针对Adhoc网络中移动节点能量受限的问题,考虑节点剩余能量和节点能量消耗速率两方面因素,对AODV协议,在选路机制,hello机制几个方面作了改进,改进后的路由协议能够有效均衡负载,保护低能量节点,延长网络生存时间。 相似文献
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无线传感器网络中节点的位置信息非常重要,目前通用的定位算法不适合恶劣环境;路由算法的设计直接影响到系统的能量消耗。在此提出一种基于测距的节点定位方案,并构建基于睡眠机制、最小成本路径的节能路由算法,通过理论分析和仿真实验,证明该算法具有较高的节能性,能提高网络的整体性能。 相似文献
7.
无线传感器网络作为一种新型的以采集数据为目的、高密度、自组织、低数据率的短距离无线通信网络,在国外相关研究领域一直是热点.文章概要地介绍了无线传感器网络的特点、应用前景以及研究热点,强调了无线传感器网络的路由协议设计方式不同于现有的有线及无线网络.特别阐明了作为一个以环境监测为主要应用的自组织网络,在现有器件的条件下,网络寿命这一关键参数主要取决于对传感器节点的能耗有重大影响的路由协议,着重研究了如何从网络层的路由协议和算法设计着手实现功率控制,以达到节约能耗、延长网络寿命这一目的. 相似文献
8.
无线传感器网络因其明显的性能优势和巨大的应用前景而受到学术界和工业界越来越广泛的重视。在无线传感器体系结构中,网络层路由协议是无线传感网络的核心问题。文章阐述了无线传感器网络的特点,路由协议的要求,并对重要的路由协议工作原理进行了技术分析,从协议性能的角度比较了各个路由协议的特点,最后在文中对WSN路由协议的研究仍存在的问题和挑战进行了论述,指出了未来无线传感器网络路由协议的研究方向。 相似文献
9.
Wireless sensor networks consist of hundreds or thousands of sensor nodes that involve numerous restrictions including computation capability and battery capacity. Topology control is an important issue for achieving a balanced placement of sensor nodes. The clustering scheme is a widely known and efficient means of topology control for transmitting information to the base station in two hops. The automatic routing scheme of the self-organizing technique is another critical element of wireless sensor networks. In this paper we propose an optimal algorithm with cluster balance taken into consideration, and compare it with three well known and widely used approaches, i.e., LEACH, MEER, and VAP-E, in performance evaluation. Experimental results show that the proposed approach increases the overall network lifetime, indicating that the amount of energy required for communication to the base station will be reduced for locating an optimal cluster. 相似文献
10.
Cross-layer design of energy-saving AODV routing protocol 总被引：1，自引：0，他引：1
Since most ad hoc mobile devices today operate on batteries, the power consumption becomes an important issue. This paper proposes a cross-layer
design of energy-aware ad hoc on-demand distance vector (CEAODV) routing protocol which adopts cross-layer mechanism and energy-aware metric to improve
AODV routing protocol to reduce the energy consumption and then prolong the life of the whole network. In CEAODV, the link
layer and the routing layer work together to choose the optimized transmission power for nodes and the route for packets.
The link layer provides the energy consumption information for the routing layer and the routing layer chooses route accordingly
and conversely controls the link layer to adjust the transmission power. The simulation result shows that CEAODV can outperform
AODV to save more energy. It can reduce the consumed energy by about 8% over traditional energy-aware algorithm. And the performance
is better when the traffic load is higher in the network. 相似文献
11.
Kyle L. Peck 《TechTrends》1998,43(2):47-53
Conclusion I applaud ISTE, AASL, AECT, and the other organizations involved for tackling the “messy work” of developing standards for
the use of technology and information resources in schools. And, at the same time, I call for a “second generation” of standards
that define realistic expectations for teachers based on the subjects and levels they are called upon to teach. I propose
that professional organizations from each subject work with ISTE and AECT to complete this huge task, and I propose that we
consider as a “next step” the creation of a set of on-line learning experiences through which teachers can gain the identified
skills and knowledge by using the very technologies we’re hoping they’ll embrace in their own teaching.
There’s an old saying, “If you don’t know where you’re going, any road will do.” As far as educational technologies are concerned,
this is also true. For many, the goal seems to have been simply to “get more computers into the schools,” without much thought
about purpose. To return to Phil Schlechty’s metaphor, It’s generally been a brief and misguided “Ready” stage (occupied with
questions like “How many do we need?” “What type?” “Where?” and “How shall we connect them?”), followed by “Fire!” (the acquisition
and installation of equipment). What we need is: “Ready” (the creation of appropriate teams of people who will combine their
insights to plan for the district)... “Aim” (a series of discussions about what technologies can accomplish for schools and
the students they serve)... “Fire” (acquisition, installation, and professional development according to plan)... “Aim” (an
assessment of how well the technologies and related programs met the intended goals, and a new planning effort designed to
close the gap)... “Fire” (acquisition and implementation designed to eliminate the gap)... “Aim” (another gap assessment)...
“Fire” (another attempt to close gaps)..., And so on. 相似文献
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针对无线传感器网络中覆盖空洞的现象,提出一种基于虚拟力的解决办法。为减少节点由移动所带来的能量消耗,该方法最多选择3个节点,通过节点移动并扩大其感知半径来修复覆盖空洞。实验结果表明该方法能保证较好的网络覆盖率,延长网络的生存时间。 相似文献
14.
方捻 《上海大学学报(英文版)》2006,10(4):373-374
All optical network (AON) is a hot topic in recentstudies of optical fiber communications . Key tech-niques in AONinclude optical switching/routing,opti-cal cross connection ( OXC) , all optical wavelengthconversion (AOWC) ,all optical buffering,etc. Opti… 相似文献
15.
Kamal Ahuja 《Resonance》2011,16(10):956-959
The 2010 Nobel Prize in Physiology or Medicine was awarded to Dr. Robert Edwards for “the development of in vitro fertilization”.
The Nobel Assembly stated that the vision Edwards had of discovering a treatment for infertility is now “a reality and brings
joy to infertile people all over the world”. Indeed, looking back over my own familiarity with Edwards and with the treatment
of infertility by in vitro fertilization (IVF), I can think of only very few — if any — disciplines in medicine that owe their origins and their progress
so much to just one man. For Edwards it was his controversial experiments in oocyte maturation and fertilization that paved
the way for IVF. With the gynaecologist Patrick Steptoe, he successfully pioneered the birth of the world’s first IVF baby
in July 1978, and thereby, in that single event, opened the door to IVF for so many individuals and clinics around the world. 相似文献
16.
为了均衡传统分簇路由算法中的簇间传输能耗,减少簇首更换开销,提出基于最优化模型的能耗均衡分簇路由协议 opt_leach。将区域节点划分成大小相同的簇,均衡不同簇的簇内通信开销;簇间通信采用多种路由组合的方式通信,均衡簇间通信开销;簇内节点可以连续充当簇首,减少簇首更换开销。实验结果表明,与传统分簇路由算法相比,该算法可更好地实现能耗均衡,延长网络生存时间。 相似文献
17.
In this paper, the open queueing network model is proposed for solving the problem of public transportation in cities. The
vertices of the networks (i.e., the bus stops) are determined by means of the fuzzy clustering method. The arcs (i.e., the
paths of the public transportation) can be set up by using the shortest path model in the time sense or the 0–1 integer programming
method. Applying the statistics method, we can calculate the parameters (such as the passenger flow’s distribution, passenger
flow’s transition probability, mean waiting time for the bus etc.) of the public transportation network. In this paper, we suggest to divide the network into two or three stages to implement
the public transportation system in the form of “frog jumping” fast transfer and “permeation” fast dispersion. Combining the
computer simulation and the evaluation of the achievement and effect of public transportation system, we modify the model
so as to solve the public transportation problem better. 相似文献
18.
Wang Hong-yu 《浙江大学学报(A卷英文版)》2000,1(3):254-263
In this paper, the author proposes a new virtual topology, referred to as fully connected cubic network (FCCN), for the wavelength
division multiplexing (WDM) multihop lightwave network. The FCCN is a multi-level, highly scalable and modular architecture.
Anm level FCCN is constructed by “fully connecting” 8 (m−1)-FCCNs. The FCCN satisfies very well all the design requirements for WDM lightwave networks. The nodal degree is no more
than four, and independent of the network size. Both the diameter and the average hop distance are in the order of
. Owing to the highly scalable structure, the routing algorithm proposed in this paper is very simple to implement. Wavelengths
reuse technique can be applied with high efficiency to FCCN.
Project supported by Zhejiang University Cao Guangbiao Technology Development Funding(413C01302*29808) 相似文献
19.
Word sense disambiguation using semantic relatedness measurement 总被引：5，自引：0，他引：5
YANG Che-Yu 《浙江大学学报(A卷英文版)》2006,7(10):1609-1625
INTRODUCTION The need to determine the degree of semantic similarity, or more generally, relatedness, between two lexically expressed concepts is applied in such ap- plications as word sense disambiguation (WSD), determining discourse structure, text summarization and annotation, information extraction and retrieval, automatic indexing, lexical selection, and automatic correction of word errors in text. All human languages have words that can mean different things in different contexts, s… 相似文献
20.
陈亦萍 《三明高等专科学校学报》2013,(4):24-29
利用多人博弈的思想对簇内节点间协作和竞争的关系进行分析,提出一种簇内信息融合算法。通过仿真实验对节点能量消耗的均衡性、网络生存周期及信息融合精度等方面进行性能评估验证该算法的有效性。 相似文献